class_docstr: [summary]
  
  Args:
    test {[type]} -- [description]
docstr: Test list directory.
docstr_tok: ["Test","list","directory","."]
code: def test_list_directory(self):
      """Test list directory."""
      # Setup and check preconditions.
      dir_name = self._path_to("listdir")
      file_names = [self._path_to(f"listdir/{i}") for i in range(1, 4)]
  
      for file_name in file_names:
          with tf.io.gfile.GFile(file_name, "w") as w:
              w.write("")
      # Get list of files in directory.
      ls_result = tf.io.gfile.listdir(dir_name)
      # Check that list of files is correct.
      self.assertEqual(len(file_names), len(ls_result))
      for e in ["1", "2", "3"]:
          self.assertTrue(e in ls_result)
  
imports: import os
  import subprocess
  import sys
  import pytest
  import tensorflow
  import tensorflow_io
label_desc: Use image node_id 10 for calling the AZFSTestBase obj's underlying member method code with example usage: obj.test_list_directory() without return types